scholarly journals Continuum-scale investigation of evaporation from bare soil under different boundary and initial conditions: An evaluation of nonequilibrium phase change

2015 ◽  
Vol 51 (9) ◽  
pp. 7630-7648 ◽  
Author(s):  
Andrew C. Trautz ◽  
Kathleen M. Smits ◽  
Abdullah Cihan
Keyword(s):  
Phase Change ◽  
Initial Conditions ◽  
Bare Soil ◽  
Nonequilibrium Phase ◽  
Continuum Scale

scholarly journals On the applicability of continuum scale models for ultrafast nanoscale liquid-vapor phase change

2021 ◽  
Vol 135 ◽  
pp. 103508
Author(s):  
Anirban Chandra ◽  
Zhi Liang ◽  
Assad A Oberai ◽  
Onkar Sahni ◽  
Pawel Keblinski
Keyword(s):  
Phase Change ◽  
Vapor Phase ◽  
Scale Models ◽  
Continuum Scale ◽  
Liquid Vapor

Geometric phase of two-qubit system in dephasing environment

2015 ◽  
Vol 29 (32) ◽  
pp. 1550236 ◽  
Author(s):  
Xiaoya Cai ◽  
Hui Pan ◽  
Z. S. Wang
Keyword(s):  
Phase Change ◽  
Quantum Computation ◽  
Geometric Phase ◽  
Berry Phase ◽  
Initial Conditions ◽  
The Other ◽  
Time Dependent ◽  
Pancharatnam Phase ◽  
Coupling System ◽  
Qubit System

We investigated the geometric phase for interaction between superconducting two-qubit system in dephased environment. The Pancharatnam phase and the Berry phase are studied. Numerical results are discussed. By considering the differently initial conditions, we find that the time-dependent Pancharatnam phase keeps the initial entangling message. On the other hand, the transition of Pancharatnam phase is dependent of the phase change in the superconducting two-qubit coupling system. Our results may be helpful to implement the time-dependent geometric quantum computation.

Phase-Change in Finite Slabs With Time-Dependent Convective Boundary Conditions

Volume 3 ◽  
2004 ◽  
Author(s):  
Anand P. Roday ◽  
Michael J. Kazmierczak
Keyword(s):  
Phase Change ◽  
Change Process ◽  
Initial Conditions ◽  
Convective Boundary Condition ◽  
Liquid Interface ◽  
Convective Boundary ◽  
Phase Change Process ◽  
The Right ◽  
Solid Liquid Interface ◽  
Solid Liquid

The heat balance integral method is used to solve one-dimensional phase-change problem in a finite slab with time-dependent convective boundary condition, [T∞,1(t)], applied at the left face. The temperature, T∞,1(t), decreases linearly with time; the other face of the slab is subjected to a constant convective boundary condition with T∞,2 held fixed at the ambient temperature. Two initial conditions are investigated: temperature of the solid below the melting point (subcooled), and initially at the fusion temperature (Tf). The temperature, T∞,1(t) at time t = 0 is so chosen such that convective heating takes place and the slab begins to melt (i.e., T∞,1(0)> Tf> T∞,2). Thus the solid-liquid interface proceeds forward to the right. As time continues, and T∞,1(t) decreases with time, the phase-change front slows, stops, and may even reverse direction. Hence this problem features sequential melting and freezing of the slab with partial penetration of the solid-liquid front before reversal of the phase-change process. It should, however, be noted that the study is limited to only one solid-liquid interface at any given time during the phase-change process (either melting or freezing) and that slight subcooling of the melt is allowed. The effect of varying the Biot number at the right face of the slab, for both the initial conditions, is also investigated to determine its impact on the growth/recession of the solid-liquid interface. Temperature profiles in both regions (liquid and solid) are reported in detail. The effect of a slower decay rate of T∞,1(t) on the phase-change process is also analyzed for the initial condition of the slab being at the fusion temperature.

Hydrogen Fast Fill Modeling and Optimization of Cylinders Lined With Phase Change Material

2020 ◽  
Author(s):  
Miroslaw Liszka ◽  
Aleksandr Fridlyand ◽  
Ambalavanan Jayaraman ◽  
Michael Bonnema ◽  
Chakravarthy Sishtla
Keyword(s):  
Heat Capacity ◽  
Phase Change ◽  
Phase Change Material ◽  
Initial Conditions ◽  
Filling Process ◽  
Ansys Fluent ◽  
Single Temperature ◽  
Change Material ◽  
Capacity Method ◽  
Gas Properties

Abstract This work is a continuation of a previous study (IMECE2019-11449) which sought to explore the feasibility and means of successfully modeling the hydrogen fast filling process of cylinders lined with phase change material (PCM) entirely in CFD software. The first focus of this work was to address the simplistic approach of how the liner temperature was modelled in the previous study. Previously, the entire liner was assigned a single temperature which was obtained and updated through the lumped heat capacity method. This meant that the hotter gas at the end of the cylinder opposite the inlet was in contact with a liner at a temperature lower than could realistically be expected. This was remedied by splitting the liner into four sections. Two sections were used for the curved portions at each end of the cylinder, and the straight wall section was split into two. Each section had its temperature independently calculated through the lumped heat capacity method. A temperature difference on the order of a ten degrees Celsius was observed between the different sections of the liner prior to latent heating beginning. The mass averaged temperature of the hydrogen inside the cylinder obtained with the sectioned wall case matched that obtained with the single wall temperature almost exactly, less than a degree difference. Despite the unexpected findings of the average hydrogen temperature not changing much when the wall is split into sections, this approach was still taken with all the cases completed in this study. The liner could be split into a greater amount of sections than four, but this was considered unnecessary due to the findings regarding the overall hydrogen temperature. Four sections were considered adequate and used to model the temperature gradient along the wall or liner. The effect of gravity on the filling process was also explored based on the orientation of the cylinder. This required completing three-dimensional simulations to accurately simulate buoyancy driven flow in horizontally mounted cylinders. All the simulations were completed with ANSYS Fluent 2019 R1 without the use of additional software to handle the heat transfer involving the PCM. All simulations were completed with the coupled pressure-based solver and K-Omega SST turbulence model. The gas properties were obtained from tables generated from NIST properties (REFPROP) available within ANSYS Fluent to limit the amount of error in the accumulated mass within the cylinder due to inaccurate gas properties. The initial conditions for the gas and liner temperatures were 25°C and 100 bar for the gas pressure. A constant mass flow rate of 0.02174 kg/s at a temperature 0°C were used as the initial conditions for the inlet hydrogen gas.

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